Statistics have shown that interventions in fire situations present important risks. In particular, firefighters suffer from heat and smoke caused by the fire and need to alert other fire fighting personnel for assistance. Personal alert safety system (PASS) devices are designed to assist firefighters during their mission. PASS devices provide audible alarms and/or visual indications responsive to various undue conditions.
Generally, PASS devices detect firefighter motion, surrounding temperature, air pressure of self contained breathing apparatus (SCBA) cylinders etc. If the PASS device detects the immobility of the firefighter, the PASS device generates a loud alarm to alert other personnel that a firefighter is in a hazardous situation. It helps to guide rescue personnel to the location of the incapacitated firefighter.
Known PASS devices may include controls to manually initiate an emergency alarm. If the firefighter is in a hazardous situation and wants to warn others, then the firefighter can manually initiate the alarm. Among the reasons for the firefighter to manually initiate an emergency alarm could be if the firefighter has any problem with the SCBA, if the firefighter is trapped somewhere, if the firefighter is under a collapsed structure and can't move, if the firefighter is injured or almost unconscious, or if the firefighter is surrounded by the fire.
Some known PASS devices provide for manual activation of the emergency alarm by the use of an electromechanical push button system. For example, the emergency alarm can be manually generated by pushing a button. The aim of this alarm is to alert others that a firefighter is in hazardous situation. It helps to guide rescue personnel to the location of the incapacitated firefighter.
One such PASS device uses a coupling between a sensor such as a reed switch and a magnet. The magnet is push by a plastic part (the button) to approach the reed switch. The reed switch is placed inside the device. The magnetic field of the magnet has enough power of attraction to close the reed switch. The reed switch is part of a non-contact position detector which connects directly to the interrupt input of a microcontroller.
Concerns may exist due to sensors being sensitive to electromagnetic fields or to antistatic plastic. Also, the buttons can wear out the button may be difficult to operate.
This application is directed to improvements in personal alert safety system devices.